# Thermochemistry and Thermodynamics Test 2

Total Questions:50 Total Time: 75 Min

Remaining:

## Questions 1 of 50

Question:Which of the following units represents the largest amount of energy

Electron volt

Erg

Joule

Calorie

## Questions 2 of 50

Question:Energy equivalent to one erg, one joule and one calorie is in the order

$$1\,erg\, > \,1\,joule\, > \,1\,calorie$$

$$1\,erg\, > \,1\,calorie\, > \,1\,joule$$

$$1\,calorie\, > \,1\,joule\, > \,1\,erg$$

$$1\,joule\, > \,1\,calorie\, > \,1\,erg$$

## Questions 3 of 50

Question:In thermodynamics which one of the following is not an intensive property

Pressure

Density

Volume

Temperature

## Questions 4 of 50

Question:If in a container neither mass and nor heat exchange occurs then it constitutes a

Closed system

Open system

Isolated system

Imaginary system

## Questions 5 of 50

Question:"The resultant heat change in a reaction is the same whether it takes place in one or several stages." This statement is called

Lavoisier and Laplace law

Hess's law

Joule's law

Le'chatelier's principle

## Questions 6 of 50

Question:Hess's law of constant heat summation in based on

$$E = m{c^2}$$

Conservation of mass

First law of thermodynamics

None of the above

## Questions 7 of 50

Question:The relation between change in internal energy $$(\Delta E)$$, change in enthalpy $$(\Delta H)$$ and work done (W) is represented as

$$\Delta H = \Delta E + W$$

$$W = \Delta E - \Delta H$$

$$\Delta E = W - \Delta H$$

$$\Delta E = \Delta H + W$$

## Questions 8 of 50

Question:The enthalpy of neutralization of which of the following acids and bases is nearly $$- 13.6\,Kcal$$

HCN and NaOH

HCl and KOH

HCl and NaOH

HCl and $$N{H_4}OH$$

2 and 3 are correct

## Questions 9 of 50

Question:The work done by a system is 8 joule, when 40 joule heat is supplied to it. What is the increase in internal energy of system

25 J

30 J

32 J

28 J

## Questions 10 of 50

Question:A system absorb 600J of heat and work equivalent to 300J on its surroundings. The change in internal energy is

300 J

400 J

500 J

600 J

## Questions 11 of 50

Question:Work done during isothermal expansion of one mole of an ideal gas from 10 atom. to 1 atm at 300K is

4938.8 J

4138.8 J

5744.1 J

6257.2 J

## Questions 12 of 50

Question:For a reversible spontaneous change $$\Delta S$$ is

$$\frac{{\Delta E}}{T}$$

$$\frac{{P\,\Delta V}}{T}$$

$$\frac{q}{T}$$

RT log K

## Questions 13 of 50

Question:When disorder of a system increases, the change is said to be

Exothermic

Non-spontaneous

Endothermic

Spontaneous

## Questions 14 of 50

Question:The spontaneous flow of heat is always

From low to high pressure

From high to high pressure

Unidirectional from lower temperature to higher temperature

Unidirectional from the higher to lower temperature

## Questions 15 of 50

Question:The occurrence of a reaction is impossible if

$$\Delta H$$ is +ve ; $$\Delta S$$ is also + ve but $$\Delta H < T\Delta S$$

$$\Delta H$$ is – ve ; $$\Delta S$$ is also – ve but $$\Delta H\, > \,T\Delta S$$

$$\Delta H$$ is – ve ; $$\Delta S$$ is + ve

$$\Delta H$$ is + ve ; $$\Delta S$$ is – ve

## Questions 16 of 50

Question:If the enthalpy of vaporization for water is 186.5 kJ $$mo{l^{ - 1}}$$, the entropy of its vaporization will be

$$0.5\,J{K^{ - 1}}mo{l^{ - 1}}$$

$$1.0\,J{K^{ - 1}}mo{l^{ - 1}}$$

$$1.5\,J{K^{ - 1}}mo{l^{ - 1}}$$

$$2.0\,J{K^{ - 1}}mo{l^{ - 1}}$$

## Questions 17 of 50

Question:Which of the following statement is true. The entropy of the universe

Increases and tends towards maximum value

Decreases and tends to be zero

Remains constant

Decreases and increases with a periodic rate

## Questions 18 of 50

Question:One mole of an ideal gas at $$300K$$ is expanded isothermally from an initial volume of 1 litre to 10 litres. The change in energy for this process is $$(R = 2\,cal\,mo{l^{ - 1}}{K^{ - 1}})$$

163.7 cal

850.2 cal

1381.1 cal

Zero

## Questions 19 of 50

Question:If $$900\,J/g$$ of heat is exchanged at boiling point of water, then what is increase in entropy

43.4 J/mole

87.2 J/mole

900 J/mole

Zero

## Questions 20 of 50

Question:A container has hydrogen and oxygen mixture in ratio of 4 : 1 by weight, then

Internal energy of the mixture decreases

Internal energy of the mixture increases

Entropy of the mixture increases

Entropy of the mixture decreases

## Questions 21 of 50

Question:Equal volumes of monoatomic and diatomic gases at same initial temperature and pressure are mixed. The ratio of specific heats of the mixture $$({C_p}/{C_v})$$ will be

1

2

1.67

1.5

## Questions 22 of 50

Question:The law formulated by Dr. Nernst is

First law of thermodynamics

Second law of thermodynamics

Third law of thermodynamics

Both 1 and 2

## Questions 23 of 50

Question:Entropy is maximum in case of

Steam

Water at $${0^o}C$$

Water at $${4^o}C$$

Ice

## Questions 24 of 50

Question:Considering entropy (S) as a thermodynamic parameter, the criterion for the spontaneity of any process is

$$\Delta {S_{system}} > 0$$ only

$$\Delta {S_{surroundings}} > 0$$ only

$$\Delta {S_{system}} + \Delta {S_{surroundings}} > 0$$

$$\Delta {S_{system}} - \Delta {S_{surroundings}} > 0$$

## Questions 25 of 50

Question:An exothermic reaction is one which

Takes place only on heating

Is accompanied by a flame

Is accompanied by a absorption of heat

Is accompanied by evolution of heat

## Questions 26 of 50

Question:An endothermic reaction is one in which

Heat is converted into electricity

Heat is absorbed

Heat is evolved

Heat is converted into mechanical work

## Questions 27 of 50

Question:The enthalpy of combustion at 25$$^\circ$$C of $${H_2}$$, cyclohexane (C$$_{\rm{6}}$$H$$_{{\rm{12}}}$$) and cyclohexene (C$$_{\rm{6}}$$H$$_{{\rm{1}}0}$$) are -241, -3920 and -800 KJ / mole respectively. The heat of hydrogenation of cyclohexene is

121 KJ / mole

+ 121 KJ / mole

242 KJ / mole

+ 242 KJ / mole

## Questions 28 of 50

Question:Heat of neutralisation of $$N{H_4}OH$$ and $$HCl$$ is

$$13.7\,kcal$$

$$> \,13.7\,kcal$$

$$< \,13.7\,kcal$$

None of the above

## Questions 29 of 50

Question:The heat of combustion of carbon is –94 kcal at 1 atm pressure. The intrinsic energy of $$C{O_2}$$ is

$$+ 94\,kcal$$

$$- \,94\,kcal$$

$$+ 47\,kcal$$

$$- 47\,kcal$$

## Questions 30 of 50

Question:The heat of neutralisation of a strong acid and a strong alkali is $$57.0\,kJ\,mo{l^{ - 1}}$$. The heat released when $$0.5\,mole$$ of $$HN{O_3}$$ solution is mixed with $$0.2\,mole$$ of $$KOH$$ is

$$57.0\,kJ$$

$$11.4\,kJ$$

$$28.5\,kJ$$

$$34.9\,kJ$$

## Questions 31 of 50

Question:One of the phenomena which cannot be described as combustion is

Oxidation of coal in air

Burning of magnesium in nitrogen

Reaction of antimony in chlorine

Lighting of an electric lamp

## Questions 32 of 50

Question:Which of the following statements is correct about heat of combustion

It may be exothermic in some cases and endothermic in other cases

It is applicable to gaseous substances only

It is always an exothermic reaction

Its value does not change with temperature

## Questions 33 of 50

Question:Based on the following thermochemical equations $${H_2}O(g) + C(s) \to CO(g) + {H_2}(g);\,\Delta H = 131\,kJ$$, $$CO(g) + \frac{1}{2}{O_2}(g) \to C{O_2}(g);\Delta H = - 282\,kJ$$, $${H_2}(g) + \frac{1}{2}{O_2}(g) \to {H_2}O(g);\,\Delta H = - 242\,kJ$$ , $$C(s) + {O_2}(g) \to C{O_2}(g);\,\Delta H = X\,kJ$$ . The value of $$X$$ is

$$- 393\,kJ$$

$$- \,655\,kJ$$

$$+ \,393\,kJ$$

$$+ 655\,kJ$$

## Questions 34 of 50

Question:Heat of transition is the heat evolved or absorbed when a substance is converted from

Solid to liquid

Solid to vapour

Liquid to vapour

One allotropic form to another allotropic form

## Questions 35 of 50

Question:In an endothermic reaction, the value of $$\Delta H$$ is

Zero

Positive

Negative

Constant

## Questions 36 of 50

Question:$$2.2016\,gm$$ of acetaldehyde produced $$13.95\,kcal$$ of heat on combustion in $${O_2}$$. Calculate the heat of combustion of $$C{H_3}CHO$$

279 kcal

972 kcal

27.9 kcal

2.79 kcal

## Questions 37 of 50

Question:The neutralisation of a strong acid by a strong base liberates an amount of energy per mole of $${H^ + }$$ that

Depends upon which acid and base are involved

Depends upon the temperature at which the reaction takes place

Depends upon which catalyst is used

Is always the same

## Questions 38 of 50

Question:When $$0.5g$$ of sulphur is burnt to $$S{O_2},\,4.6\,kJ$$ of heat is liberated. What is the enthalpy of formation of sulphur dioxide

+ 147.2 kJ

147.2 kJ

294.4 kJ

+ 294.4 kJ

## Questions 39 of 50

Question:$${H_2}(g) + C{l_2}(g)\,\, \to \,\,2HCl(g)\,.\,\Delta H = - 44kcal$$, $$2Na(s) + 2HCl(g)\,\, \to \,\,2NaCl(s) + {H_2}(g),$$$$\Delta H = - 152\,kcal$$, For the reaction $$Na(s) + \frac{1}{2}C{l_2}(g)\,\, \to \,\,NaCl(s),\,\Delta H =$$

-108 kcal

-196 kcal

-98 kcal

-54 kcal

## Questions 40 of 50

Question:The $$\Delta H_f^o$$ for $$C{O_2}(g),\,CO(g)$$ and $${H_2}O(g)$$ are -393.5, -110.5 and -241.8kJmol$$^{ - 1}$$ respectively. The standard enthalpy change (in kJ) for the reaction $$C{O_2}(g) + {H_2}(g) \to$$ $$CO(g) + {H_2}O(g)$$ is

524.1

41.2

262.5

41.2

## Questions 41 of 50

Question:Heat of neutralization of strong acid and weak base is

$$57.1\,kJ\,mo{l^{ - 1}}$$

$$13.7\,kJ\,mo{l^{ - 1}}$$

Less than $$13.7\,kcal\,mo{l^{ - 1}}$$

More than $$13.7\,kcal\,mo{l^{ - 1}}$$

## Questions 42 of 50

Question:A system is changed from state A to state B by one path and from B to A another path. If $${E_1}$$ and $${E_2}$$ are the corresponding changes in internal energy, then

$${E_1} + {E_2} = - ve$$

$${E_1} + {E_2} = + ve$$

$${E_1} + {E_2} = 0$$

None of these

## Questions 43 of 50

Question:One gram sample of $$N{H_4}N{O_3}$$ is decomposed in a bomb calorimeter. The temperature of the calorimeter increases by 6.12 K the heat capacity of the system is 1.23 kJ/g/deg. What is the molar heat of decomposition for $$N{H_4}N{O_3}$$

7.53 kJ/mol

398.1 kJ/mol

16.1 kJ/mol

602 kJ/mol

## Questions 44 of 50

Question:For which one of the following equations is $$\Delta H_{{\rm{react}}}^o$$ equal to $$\Delta H_f^o$$ for the product

$$2CO(g) + {O_2}(g)\, \to \,2C{O_2}(g)$$

$${N_2}(g) + {O_3}(g)\, \to \,{N_2}{O_3}(g)$$

$$C{H_4}(g) + 2C{l_2}(g)\, \to \,C{H_2}C{l_2}(l) + 2HCl(g)$$

$$Xe(g) + 2{F_2}(g)\, \to \,Xe{F_4}(g)$$

## Questions 45 of 50

Question:If the bond dissociation energies of $$XY,\,{X_2}$$and $${Y_2}$$ (all diatomic molecules) are in the ratio of 1 : 1 : 0.5 and $${\Delta _f}H$$ for the formation of $$XY$$ is $$- 200\,kJ\,mol{e^{ - 1}}$$. The bond dissociation energy of $${X_2}$$ will be

$$100\,kJ\,mo{l^{ - 1}}$$

$$800\,kJ\,mo{l^{ - 1}}$$

$$300\,kJ\,mo{l^{ - 1}}$$

$$400\,kJ\,mo{l^{ - 1}}$$

## Questions 46 of 50

Question:Energy required to dissociate 4 gm of gaseous hydrogen into free gaseous atoms is 208 kcal at $${25^o}C$$. The bond energy of $$H - H$$ bond will be

104 kcal

10.4 kcal

1040 kcal

104 cal

## Questions 47 of 50

Question:For precipitation reaction of $$A{g^ + }$$ ions with $$NaCl$$, which of the following statements is correct

$$\Delta H$$ for the reaction is zero

$$\Delta G$$ for the reaction is zero

$$\Delta G$$ for the reaction is negative

$$[\Delta G] = [\Delta H]$$

## Questions 48 of 50

Question:At constant pressure and temperature, the direction to the result of any chemical reaction is where, there is less amount of

Entropy

Enthalpy

Gibb's free energy

None of the above

## Questions 49 of 50

Question:The equilibrium concentration of the species in the reaction $$A + B \equiv C + D$$ are 3, 5, 10 and 15 $$mole\,{L^{ - 1}}$$ respectively at $$300\,K$$ the $$\Delta G$$ for the reaction is

13.81

1381.8

138.18

1391.6

## Questions 50 of 50

Question:Gibb's free enrgy $$(G)$$ is defined as

$$\Delta G = \Delta H - T\Delta S$$
$$\Delta G = \Delta H + \frac{T}{{\Delta S}}$$
$$\Delta H = \Delta G - T\Delta S$$
$$\Delta G = \Delta H + T.{C_p}$$